Season 1

Myonghwan meets Kang Dojun and Inju at the apprentice library. There, they share their hopes and dreams together. However, after they find out the secret behind the Crown Prince's assassination, they are faced with grave danger...

Songha tells Kwanghyon that he can't get with Jinyoung since he's a commoner and she's a noble. The nurse finds out that Oh Jangbak is from the same island as Kwanghyon. During the practical application, Kwanghyon faces the king...

Yi Myonghwan tries to stop Lord Ko from treating the king, but Kwanghyon helps him. The nurse tells Kwanghyon that someone poisoned him on purpose, and Lady Shin tells him to be careful of Yi Myonghwan.

The Empress has been diagnosed with sequestrum. Physicians from different areas are brought together to find a cure. They use surrogates before they start the actual treatment on the Empress, and Kwanghyon tries to come up with a cure for tetanus.

A man with Onguk's Guide to Sores shows up and tells Yi Myonghwan that he doubts Kwanghyon's abilities to treat the Crown Prince. They face danger when the Crown Prince doesn't stop bleeding from the surgery...

The doctors find out that the cure to smallpox is to adjust the treatment for each stage of the disease. However, Dr. Choi manages to make the Princess's condition worse and Kwanghyon tries to stop it...

Jinyoung gets freed from being a slave, however the officials are against their marriage since Kwanghyon's from the capital's finest family. The viceroy pressures him into entering the public service...